What would prevent a user from syncing a quote with an opportunity?

Another quote is already synced with the opportunity will prevent a user from syncing a quote with an opportunity. Only one quote can be synced with an opportunity at a time. If a user tries to sync another quote, they will get an error message saying that the opportunity already has a synced quote. References: https://help.salesforce.com/s/articleView?id=sf.quotes_syncing.htm &type=5